There are a few things you got to do religiously before you start seeking new customers.

Honesty is the best policy… so be honest.
What goes around, comes around.. so try and help when somebody asked for your services.
Be reasonable. Never “overbill” your customers.
Put your point across in a very clear but humble manner. Try keeping everything on paper to leave no scope for confusion later.
Don’t indulge in any false selling. You can fool your customer the first time but not every time.
Customer satisfaction should be the top priority. If your customer is happy with your work, he will totally forget about sharing his experience with other.. but on the other hand, if he is not happy, he will tell everyone.
Now about how to find customers. If you look around carefully, they are everywhere. Find them in your social network, business network, and friends. And if you don’t have any network yet, start building the one. Business comes only from known people because nobody trusts strangers.

You can ask your existing customers to provide you references.
Tell your friends what new you are doing
Make use of Facebook and Twitter to reach out to your potential customers.
Invest in SEO and Adwords Campaign.
Act proactively when you receive inquiries